Eric Dumazet 5f3e2bf008 tcp: add tcp_min_snd_mss sysctl ... Some TCP peers announce a very small MSS option in their SYN and/or SYN/ACK messages. This forces the stack to send packets with a very high network/cpu overhead. Linux has enforced a minimal value of 48. Since this value includes the size of TCP options, and that the options can consume up to 40 bytes, this means that each segment can include only 8 bytes of payload. In some cases, it can be useful to increase the minimal value to a saner value. We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility reasons. Note that TCP_MAXSEG socket option enforces a minimal value of (TCP_MIN_MSS). David Miller increased this minimal value in commit c39508d6f1 ("tcp: Make TCP_MAXSEG minimum more correct.") from 64 to 88. We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS. CVE-2019-11479 -- tcp mss hardcoded to 48 Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Jonathan Looney <jtl@netflix.com> Acked-by: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Bruce Curtis <brucec@netflix.com> Cc: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2019-06-15 18:47:31 -07:00
..
caif
device_drivers	Documentation: net: move device drivers docs to a submenu	2019-05-22 12:18:20 -07:00
dsa	Documentation: net: dsa: sja1105: Add info about supported traffic modes	2019-05-05 21:52:42 -07:00
mac80211_hwsim	mac80211_hwsim: suggest nl80211 instead of wext driver in documentation	2016-10-17 11:38:01 +02:00
6lowpan.txt	docs: networking: fix minor typos in various documentation files	2018-06-04 17:21:28 -04:00
6pack.txt
af_xdp.rst	Documentation/networking: fix af_xdp.rst Sphinx warnings	2019-05-21 16:19:49 +02:00
alias.rst	docs: networking: Convert alias.txt to rst	2018-07-18 15:28:27 -07:00
altera_tse.txt
arcnet-hardware.txt
arcnet.txt
atm.txt
ax25.txt
batman-adv.rst	batman-adv: Drop documentation about sysfs files	2019-03-25 09:31:35 +01:00
baycom.txt
bonding.txt	bonding: Fix a typo in bonding.txt	2018-07-16 13:32:12 -07:00
bridge.rst	docs: networking: Convert bridge.txt to rst	2018-07-18 15:28:27 -07:00
can_ucan_protocol.rst	can: ucan: add driver for Theobroma Systems UCAN devices	2018-07-27 10:40:16 +02:00
can.rst	docs: can.rst: fix a footnote reference	2018-06-15 12:48:59 -03:00
cdc_mbim.txt	Documentation: fix usb related doc refs	2017-10-12 11:15:48 -06:00
checksum-offloads.rst	doc: networking: shorten the main title in offloads documents	2019-01-07 15:27:51 -07:00
conf.py	docs-rst: convert networking book to ReST	2017-05-16 08:44:13 -03:00
cops.txt
cxacru-cf.py
cxacru.txt
dccp.txt
dctcp.txt
decnet.txt	Documentation: decnet: remove reference to CONFIG_DECNET_ROUTE_FWMARK	2019-04-21 11:25:11 -07:00
defza.txt	FDDI: defza: Add support for DEC FDDIcontroller 700 TURBOchannel adapter	2018-10-15 21:46:06 -07:00
devlink-health.txt	devlink: Add Documentation/networking/devlink-health.txt	2019-02-07 10:34:29 -08:00
devlink-info-versions.rst	Documentation: networking: devlink-info-versions: Add fw.psid	2019-04-08 16:28:01 -07:00
devlink-params-bnxt.txt	devlink: Add Documentation/networking/devlink-params-bnxt.txt	2018-10-04 13:49:43 -07:00
devlink-params-mlxsw.txt	mlxsw: spectrum: add "acl_region_rehash_interval" devlink param	2019-02-08 15:02:50 -08:00
devlink-params.txt	devlink: Add 'fw_load_policy' generic parameter	2018-12-03 13:55:43 -08:00
dns_resolver.txt	doc: ReSTify keys-request-key.txt	2017-05-18 10:33:51 -06:00
driver.txt
eql.txt
failover.rst	net: Introduce generic failover module	2018-05-28 22:59:54 -04:00
fib_trie.txt
filter.txt	docs/bpf: minor casing/punctuation fixes	2019-03-02 00:40:04 +01:00
fore200e.txt
framerelay.txt
gen_stats.txt	net: sched: do not acquire qdisc spinlock in qdisc/class stats dump	2016-06-07 16:37:14 -07:00
generic_netlink.txt
generic-hdlc.txt
gtp.txt	docs: networking: fix minor typos in various documentation files	2018-06-04 17:21:28 -04:00
hinic.txt	net-next/hinic: Initialize hw interface	2017-08-22 10:48:52 -07:00
ieee802154.rst	doc: net: ieee802154: introduce IEEE 802.15.4 subsystem doc in rst style	2019-03-01 17:03:00 -08:00
ila.txt	docs: networking: fix minor typos in various documentation files	2018-06-04 17:21:28 -04:00
index.rst	Documentation: add TLS offload documentation	2019-05-22 12:18:20 -07:00
ip_dynaddr.txt
ip-sysctl.txt	tcp: add tcp_min_snd_mss sysctl	2019-06-15 18:47:31 -07:00
ipddp.txt
iphase.txt
ipsec.txt	docs: networking: fix minor typos in various documentation files	2018-06-04 17:21:28 -04:00
ipv6.txt
ipvlan.txt	docs: networking: fix minor typos in various documentation files	2018-06-04 17:21:28 -04:00
ipvs-sysctl.txt	ipvs: Document sysctl pmtu_disc	2017-03-16 13:33:39 +01:00
kapi.rst	sfp: add documentation for kernel APIs	2017-12-05 11:16:19 -05:00
kcm.txt	docs: networking: fix minor typos in various documentation files	2018-06-04 17:21:28 -04:00
l2tp.txt	net: l2tp: deprecate PPPOL2TP_MSG_* in favour of L2TP_MSG_*	2016-12-10 23:29:11 -05:00
lapb-module.txt
ltpc.txt
mac80211-auth-assoc-deauth.txt
mac80211-injection.txt
mpls-sysctl.txt	mpls: allow TTL propagation from IP packets to be configured	2017-03-13 15:29:22 -07:00
msg_zerocopy.rst	doc: fix link to MSG_ZEROCOPY patchset	2019-03-18 09:50:21 -07:00
multiqueue.txt
net_dim.txt	Documentation/networking: Add net DIM documentation	2018-03-22 14:50:44 -04:00
net_failover.rst	docs: networking: Fix failover build warnings	2018-07-16 11:23:54 -07:00
netconsole.txt	docs: fix locations of several documents that got moved	2016-10-24 08:12:35 -02:00
netdev-FAQ.rst	Documentation: fix netdev-FAQ.rst markup warning	2019-05-01 09:12:51 -04:00
netdev-features.txt	docs-networking: fix typo in define	2018-11-21 10:30:30 -08:00
netdevices.txt
netfilter-sysctl.txt	netfilter: allow logging from non-init namespaces	2017-02-02 14:31:58 +01:00
netif-msg.txt
nf_conntrack-sysctl.txt	netfilter: conntrack: register sysctl table for gre	2018-12-21 00:51:25 +01:00
nf_flowtable.txt	netfilter: nf_flowtable: remove duplicated transition in diagram	2019-03-19 15:02:52 +01:00
nfc.txt
openvswitch.txt
operstates.txt	Documentation: bring operstate documentation up-to-date	2019-02-11 12:38:51 -08:00
packet_mmap.txt	doc: remove out of date links and info from packet mmap	2018-03-16 10:48:52 -04:00
phonet.txt
phy.rst	Documentation: net: phy: switch documentation to rst format	2019-01-26 09:16:55 -08:00
pktgen.txt	Documentation/pktgen: Clearify how-to use pktgen samples	2018-01-24 15:03:36 -05:00
PLIP.txt
ppp_generic.txt	ppp: remove the PPPIOCDETACH ioctl	2018-05-24 22:55:07 -04:00
proc_net_tcp.txt
radiotap-headers.txt
ray_cs.txt
rds.txt	linux-next: DOC: RDS: Fix a typo in rds.txt	2019-06-12 09:56:29 -07:00
regulatory.txt	cfg80211: reg: remove support for built-in regdb	2017-10-11 13:18:51 +02:00
rxrpc.txt	rxrpc: Allow the kernel to mark a call as being non-interruptible	2019-05-16 16:25:20 +01:00
scaling.rst	doc: networking: integrate scaling document into doc tree	2019-01-20 19:10:49 -07:00
sctp.txt
secid.txt
seg6-sysctl.txt	ipv6: sr: add documentation file for per-interface sysctls	2016-11-09 20:40:06 -05:00
segmentation-offloads.rst	networking: : fix typos in code comments	2019-05-20 20:24:34 -04:00
sfp-phylink.rst	doc: add phylink documentation to the networking book	2019-02-24 12:39:45 -08:00
skfp.txt
snmp_counter.rst	networking: fix snmp_counter.rst Doc. Warnings	2019-03-17 19:37:08 -07:00
strparser.txt	strparser: Corrected typo in documentation.	2018-06-24 16:40:20 +09:00
switchdev.txt	switchdev: Remove unused transaction item queue	2019-03-01 21:35:19 -08:00
tc-actions-env-rules.txt
tcp-thin.txt
team.txt
timestamping.txt	socket: Update timestamping Documentation	2019-02-03 11:17:31 -08:00
tls-offload-layers.svg	Documentation: add TLS offload documentation	2019-05-22 12:18:20 -07:00
tls-offload-reorder-bad.svg	Documentation: add TLS offload documentation	2019-05-22 12:18:20 -07:00
tls-offload-reorder-good.svg	Documentation: add TLS offload documentation	2019-05-22 12:18:20 -07:00
tls-offload.rst	Documentation: add TLS offload documentation	2019-05-22 12:18:20 -07:00
tls.rst	Documentation: add TLS offload documentation	2019-05-22 12:18:20 -07:00
tproxy.txt	netfilter: doc: Add nf_tables part in tproxy.txt	2018-08-16 19:37:07 +02:00
tuntap.txt
udplite.txt
vrf.txt	net: provide a sysctl raw_l3mdev_accept for raw socket lookup with VRFs	2018-11-07 16:12:38 -08:00
vxlan.txt
x25-iface.txt
x25.txt
xfrm_device.txt	net: switch secpath to use skb extension infrastructure	2018-12-19 11:21:38 -08:00
xfrm_proc.txt	xfrm: update the stats documentation	2017-12-22 06:45:48 +01:00
xfrm_sync.txt
xfrm_sysctl.txt
z8530book.rst	docs-rst: convert scsi DocBook to ReST	2017-05-16 08:44:15 -03:00
z8530drv.txt